// SPDX-License-Identifier: GPL-2.0-or-later/* Network filesystem caching backend to use cache files on a premounted * filesystem * * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #include <linux/module.h>#include <linux/init.h>#include <linux/sched.h>#include <linux/completion.h>#include <linux/slab.h>#include <linux/fs.h>#include <linux/file.h>#include <linux/namei.h>#include <linux/mount.h>#include <linux/statfs.h>#include <linux/sysctl.h>#include <linux/miscdevice.h>#include <linux/netfs.h>#include <trace/events/netfs.h>#define CREATE_TRACE_POINTS#include "internal.h" unsigned cachefiles_debug;module_param_named(debug, cachefiles_debug, uint, S_IWUSR | S_IRUGO);MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask"); MODULE_DESCRIPTION("Mounted-filesystem based cache");MODULE_AUTHOR("Red Hat, Inc.");MODULE_LICENSE("GPL"); struct kmem_cache *cachefiles_object_jar; static struct miscdevice cachefiles_dev = {	.minor	= MISC_DYNAMIC_MINOR,	.name	= "cachefiles",	.fops	= &cachefiles_daemon_fops,}; /* * initialise the fs caching module */static int __init cachefiles_init(void){	int ret; 	ret = cachefiles_register_error_injection();	if (ret < 0)		goto error_einj;	ret = misc_register(&cachefiles_dev);	if (ret < 0)		goto error_dev; 	/* create an object jar */	ret = -ENOMEM;	cachefiles_object_jar =		kmem_cache_create("cachefiles_object_jar",				  sizeof(struct cachefiles_object),				  0, SLAB_HWCACHE_ALIGN, NULL);	if (!cachefiles_object_jar) {		pr_notice("Failed to allocate an object jar\n");		goto error_object_jar;	} 	pr_info("Loaded\n");	return 0; error_object_jar:	misc_deregister(&cachefiles_dev);error_dev:	cachefiles_unregister_error_injection();error_einj:	pr_err("failed to register: %d\n", ret);	return ret;} fs_initcall(cachefiles_init); /* * clean up on module removal */static void __exit cachefiles_exit(void){	pr_info("Unloading\n"); 	kmem_cache_destroy(cachefiles_object_jar);	misc_deregister(&cachefiles_dev);	cachefiles_unregister_error_injection();} module_exit(cachefiles_exit);